Digital Controller Candidate for Point-of-load Synchronous Buck Converter in Tri-mode Mechanism

Li-mei Xiu,Wei-ping Zhang,Bo Li,Yuan-sheng Liu 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.4

A digital controller with a low-power approach for point-of-load synchronous buck converters is discussed and compared with its analog counterpart to confirm its feasibility for system integration. The tri-mode digital controller IC in 0.35 μm CMOS process is presented to demonstrate solutions that include a PID, quarter PID, and robust RST compensators. These compensators address the steady-state, stand-by, and transient modes according to the system operating point. An idle-tone free condition for S?D DPWM reduces the inherent tone noise under DC-excitation. Compared with that of the traditional approach, this condition generates a quasi-pure modulation signal. Experimental results verify the closed-loop performances and confirm the power-saving mechanism of the proposed controller.

JCAD deficiency attenuates activation of hepatic stellate cells and cholestatic fibrosis

Li Xie,Hui Chen,Li Zhang,Yue Ma,Yuan Zhou,Yong-Yu Yang,Chang Liu,Yu-Li Wang,Ya-Jun Yan,Jia Ding,Xiao Teng,Qiang Yang,Xiu-Ping Liu,Jian Wu 대한간학회 2024 Clinical and Molecular Hepatology(대한간학회지) Vol.30 No.2

Background/Aims: Cholestatic liver diseases including primary biliary cholangitis (PBC) are associated with active hepatic fibrogenesis, which ultimately progresses to cirrhosis. Activated hepatic stellate cells (HSCs) are the main fibrogenic effectors in response to cholangiocyte damage. JCAD regulates cell proliferation and malignant transformation in nonalcoholic steatoheaptitis-associated hepatocellular carcinoma (NASH-HCC). However, its participation in cholestatic fibrosis has not been explored yet. Methods: Serial sections of liver tissue of PBC patients were stained with immunofluorescence. Hepatic fibrosis was induced by bile duct ligation (BDL) in wild-type (WT), global JCAD knockout mice (JCAD-KO) and HSC-specific JCAD knockout mice (HSC-JCAD-KO), and evaluated by histopathology and biochemical tests. In situ-activated HSCs isolated from BDL mice were used to determine effects of JCAD on HSC activation. Results: In consistence with staining of liver sections from PBC patients, immunofluorescent staining revealed that JCAD expression was identified in smooth muscle α-actin (α-SMA)-positive fibroblast-like cells and was significantly up-regulated in WT mice with BDL. JCAD deficiency remarkably ameliorated BDL-induced hepatic injury and fibrosis, as documented by liver hydroxyproline content, when compared to WT mice with BDL. Histopathologically, collagen deposition was dramatically reduced in both JCAD-KO and HSC-JCAD-KO mice compared to WT mice, as visualized by Trichrome staining and semi-quantitative scores. Moreover, JCAD deprivation significantly attenuated in situ HSC activation and reduced expression of fibrotic genes after BDL. Conclusions: JCAD deficiency effectively suppressed hepatic fibrosis induced by BDL in mice, and the underlying mechanisms are largely through suppressed Hippo-YAP signaling activity in HSCs.

Digital Controller Candidate for Point-of-load Synchronous Buck Converter in Tri-mode Mechanism

Xiu, Li-Mei,Zhang, Wei-Ping,Li, Bo,Liu, Yuan-Sheng The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.4

A digital controller with a low-power approach for point-of-load synchronous buck converters is discussed and compared with its analog counterpart to confirm its feasibility for system integration. The tri-mode digital controller IC in $0.35{\mu}m$ CMOS process is presented to demonstrate solutions that include a PID, quarter PID, and robust RST compensators. These compensators address the steady-state, stand-by, and transient modes according to the system operating point. An idle-tone free condition for ${\Sigma}-{\Delta}$ DPWM reduces the inherent tone noise under DC-excitation. Compared with that of the traditional approach, this condition generates a quasi-pure modulation signal. Experimental results verify the closed-loop performances and confirm the power-saving mechanism of the proposed controller.

Determination of Protein, Fat, Starch, and Amino Acids in Foxtail Millet [Setaria italica (L.) Beauv.] by Fourier Transform Near-Infrared Reflectance Spectroscopy

Xiu-Shi Yang,Li-Li Wang,Xian-Rong Zhou,Shaomin Shuang,Zhi-Hua Zhu,Nan Li,Yan Li,Fang Liu,San-Cai Liu,Ping Lu,Guixing Ren,Chuan Dong 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.6

Quantitative detection of protein, fat, starch,and amino acids in foxtail millet using Fourier transformnear-infrared spectroscopy (NIRS) was investigated. Foxtail millet samples (n=259) were analyzed using NIRS. Spectral data were linearized with data from chemicalanalyses. Calibration models were established using apartial least-squares (PLS) algorithm with cross-validation. Optimized models were tested using external validation setsamples with coefficients of determination in the externalvalidation (R2val) of >0.90. Residual predictive deviation(RPD) values were nearly equal to or >2.5 for crudeprotein, alanine, aspartic acid, glutamic acid, isoleucine,leucine, and serine. However, for glycine, histidine,phenylalanine, proline, threonine, tyrosine, and valine, theR2val values were >0.83 and RPD values were nearly equalto or >2.0. For crude fat, total starch, arginine, and lysine,the R2val values were >0.70 and RPD values were >1.5. NIRS is a rapid determination tool for foxtail milletbreeding, and for quality control.

Feasibility of Shrinking Field Radiation Therapy through 18F-FDG PET/CT after 40 Gy for Stage III Non-Small Cell Lung Cancers

Ding, Xiu-Ping,Zhang, Jian,Li, Bao-Sheng,Li, Hong-Sheng,Wang, Zhong-Tang,Yi, Yan,Sun, Hong-Fu,Wang, Dong-Qing Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.1

Objective: To explore the feasibility of shrinking field technique after 40 Gy radiation through 18F-FDG PET/CT during treatment for patients with stage III non-small cell lung cancer (NSCLC). Methods: In 66 consecutive patients with local-advanced NSCLC, 18F-FDG PET/CT scanning was performed prior to treatment and repeated after 40 Gy. Conventionally fractionated IMRT or CRT plans to a median total dose of 66Gy (range, 60-78Gy) were generated. The target volumes were delineated in composite images of CT and PET. Plan 1 was designed for 40 Gy to the initial planning target volume (PTV) with a subsequent 20-28 Gy-boost to the shrunken PTV. Plan 2 was delivering the same dose to the initial PTV without shrinking field. Accumulated doses of normal tissues were calculated using deformable image registration during the treatment course. Results: The median GTV and PTV reduction were 35% and 30% after 40 Gy treatment. Target volume reduction was correlated with chemotherapy and sex. In plan 2, delivering the same dose to the initial PTV could have only been achieved in 10 (15.2%) patients. Significant differences (p<0.05) were observed regarding doses to the lung, spinal cord, esophagus and heart. Conclusions: Radiotherapy adaptive to tumor shrinkage determined by repeated 18F-FDG PET/CT after 40 Gy during treatment course might be feasible to spare more normal tissues, and has the potential to allow dose escalation and increased local control.

Spect-guidance to Reduce Radioactive Dose to Functioning Lung for Stage III Non-small Cell Lung Cancer

Wang, Zhong-Tang,Wei, Li-Li,Ding, Xiu-Ping,Sun, Ming-Ping,Sun, Hong-Fu,Li, Bao-Sheng Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Objective: To investigate the treatment effect of additional information obtained by single photon emission computed tomography (SPECT) lung perfusion imaging (LPI) in the radiotherapy planning process for patients with stage III non-small cell lung cancer (NSCLC). Methods: 39 patients with stage III NSCLC were enrolled. Gross tumor volume (GTV) was outlined by SPECT/CT images, SPECT-LPIs being used to define functional lung (FL) and non-functional lung (NFL) regions. Two sets of IMRT plans were designed to deliver 64Gy to PTV. One was a regular IMRT plan using CT images only (Plan 1), and the other was a corresponding IMRT plan using co-registered images (Plan 2). $FL_{Vx}$ (the % volume of functional lung receiving ${\geq}$x Gy) and $WL_{Vx}$ (% volume of whole lung to receive ${\geq}$x Gy) were compared by paired Student's t test. Kendalls correlation was used to analyze the factor (s) related with the FLV20 decrease. Results: Compared with plan 1, both $WL_{Vx}$ and $FL_{Vx}$ were decreased in plan 2. $WL_{V10}$, $WL_{V15}$, $WL_{V20}$, $WL_{V25}$, $WL_{V30}$ and $WL_{V35}$ decreased 9.7%, 13.8%, 17.2%, 12.9%, 9.8% and 9.8%, and $FL_{V10}$, $FL_{V15}$, $FL_{V20}$, $FL_{V25}$, $FL_{V30}$ and $FL_{V35}$ decreased 10.8%, 14.6%, 17.3%, 14.5%, 14.5% and 10.5%. $FL_{Vx}$ decreased significantly compared with $WL_{Vx}$. There were significant differences in $WL_{V10}$, $WL_{V15}$, $WL_{V20}$, $WL_{V25}$, $WL_{V3}$ and $FL_{V10}$, $FL_{V15}$, $FL_{V20}$, $FL_{V25}$, $FL_{V30}$ between plan 1 and plan 2 (P=0.002, 0.000, 0.000, 0.005, 0.027 and 0.002, 0.000, 0.000, 0.006, 0.010). According to Kendall correlation analysis, NFL had a negative relation with the percentage FLV20 decrease (r=-0.559, P<0.01), while the distance of PTV and NFL center had a significantly positive relation with the percentage of FLV20 decrease (r=0.768, P<0.01). Conclusion: Routine use of SPECT-LPI for patients undergoing radiotherapy planning for stage III NSCLC appears warranted.

Dynamics of excitons and carriers at the NPB/C60 interface by transient photocurrents

Li Ping,De Yang Xiu,Wu Bo,Zhang Yu,Jiang Ze Zhuan,Bao Xi,Huang Hai Shen 한국물리학회 2020 Current Applied Physics Vol.20 No.5

The transient photocurrent (TPC) technique was performed to explore the dynamics of excitons and carriers at organic active layer/buffer layer interfaces. A special device with ITO/PEIE/NPB/C60/Al structure was designed to study the interfacial processes at the NPB/C60 interface. An external electrical field was provided to neutralize the built-in electrical field of the device. Interestingly, a new phenomenon was observed, wherein the polarity of the TPC changed from negative to positive under an external electrical field. The initial negative signal was ascribed to exciton separation by the built-in field in C60, and the subsequent positive signal can be attributed to the diffusion of electrons that accumulate at the NPB/C60 interface. TPC measurements shown that further increasing the external electrical field causes polarity to change twice. Analyzing the two changes in polarity revealed that the NPB did not only extract holes from C60 but also provided an effective interface for exciton dissociation.

CCNG2 Suppressor Biological Effects on Thyroid Cancer Cell through Promotion of CDK2 Degradation

Li, Wei-Juan,Liu, Ge-Ling,Yu, Fang,Xiang, Xiu-Xiu,Lu, Yi-Fang,Xiao, Hong-Zhen,Shi, Yan-Ping Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

This study aimed to analyze the expression and clinical significance of cyclin G2 (CCNG2) in thyroid carcinoma and the biological effects of CCNG2 overexpression in a cell line. Immunohistochemistry and Western blotting were used to analyze CCNG2 protein expression in 63 cases of thyroid cancer and normal tissues to allow the relationship with clinical factors to be assessed. CCNG2 lentiviral and empty vectors were transfected into the thyroid cancer K1 cell line. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were applied to detect the mRNA and protein levels of CCNG2. MTT assay and cell cycle were also conducted to assess the influence of up-regulated expression of CCNG2 on K1 cell biology. The level of CCNG2 protein expression was found to be significantly lower in thyroid cancer tissue than normal tissues (P<0.05). Western blot: The relative amount of CCNG2 protein in thyroid cancer tissue was respectively found to be significantly lower than in normal tissues (P<0.05), correlating with lymph node metastasis, clinic stage and histological grade (P<0.05), but not gender, age or tumor size (P>0.05). Loss of CCNG2 expression correlated significantly with poor overall survival time on Kaplan-Meier analysis (P<0.05). The results for biological functions showed that K1 cell transfected CCNG2 had a lower survival fraction, a greater percentage in the G0/G1 phases, and lower cyclin-dependent kinase 2 (CDK2) protein expression compared with K1 cells non-transfected with CCNG2 (P<0.05). CCNG2 expression decreased in thyroid cancer and correlated significantly lymph node metastasis, clinic stage, histological grade and poor overall survival, suggesting that CCNG2 may play important roles as a negative regulator in thyroid cancer K1 cells by promoting degradation of CDK2.

Influence of Intravenous Contrast Medium on Dose Calculation Using CT in Treatment Planning for Oesophageal Cancer

Li, Hong-Sheng,Chen, Jin-Hu,Zhang, Wei,Shang, Dong-Ping,Li, Bao-Sheng,Sun, Tao,Lin, Xiu-Tong,Yin, Yong Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.3

Objective: To evaluate the effect of intravenous contrast on dose calculation in radiation treatment planning for oesophageal cancer. Methods: A total of 22 intravein-contrasted patients with oesophageal cancer were included. The Hounsfield unit (HU) value of the enhanced blood stream in thoracic great vessels and heart was overridden with 45 HU to simulate the non-contrast CT image, and 145 HU, 245 HU, 345 HU, and 445 HU to model the different contrast-enhanced scenarios. 1000 HU and -1000 HU were used to evaluate two non-physiologic extreme scenarios. Variation in dose distribution of the different scenarios was calculated to quantify the effect of contrast enhancement. Results: In the contrast-enhanced scenarios, the mean variation in dose for planning target volume (PTV) was less than 1.0%, and those for the total lung and spinal cord were less than 0.5%. When the HU value of the blood stream exceeded 245 the average variation exceeded 1.0% for the heart V40. In the non-physiologic extreme scenarios, the dose variation of PTV was less than 1.0%, while the dose calculations of the organs at risk were greater than 2.0%. Conclusions: The use of contrast agent does not significantly influence dose calculation of PTV, lung and spinal cord. However, it does have influence on dose accuracy for heart.

Platycodin D Induces Apoptosis, and Inhibits Adhesion, Migration and Invasion in HepG2 Hepatocellular Carcinoma Cells

Li, Ting,Xu, Wen-Shan,Wu, Guo-Sheng,Chen, Xiu-Ping,Wang, Yi-Tao,Lu, Jin-Jian Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.4

Background: Platycodin D (PD), a triterpenoid saponin isolated from the Chinese medicinal herb Platycodonis radix, possesses anti-cancer effects in several cancer cell lines. The aim of this study was to evaluate its anticancer activities in hepatocellular carcinoma cells. Materials and Methods: MTT and colony formation assays were performed to evaluate cell proliferation, along with flow cytometry and Western blotting for apoptosis. Cell adhesion was tested by observing cellular morphology under a microscope, while the transwell assay was employed to investigate the cell migration and invasion. Results: PD concentration-dependently inhibited cell proliferation in both HepG2 and Hep3B cells, and significantly suppressed colony formation and induced apoptosis in HepG2 cells. The protein levels of cleaved poly ADP-ribose polymerase (PARP) and Bax were up-regulated while that of survivin was down-regulated after treatment with PD. Moreover, PD not only obviously suppressed the adhesion of HepG2 cells to Matrigel, but also remarkably depressed their migration and invasion induced by 12-O-tetradecanoylphorbol 13-acetate (TPA). Conclusions: PD presents anti-cancer potential in hepatocellular carcinoma cells via inducing apoptosis, and inhibiting cell adhesion, migration and invasion, indicating promising features as a lead compound for anti-cancer agent development.